Specific Heat

HOW MUCH HEAT CAN MY MATERIAL STORE?

Dynalene can perform specific heat testing on almost all solid and liquid sample types. The method that we most commonly use to measure specific heat for our customers differential scanning calorimetry, or DSC.

We use a differential scanning calorimeter (DSC) to precisely measure specific heat capacity. Some examples of the products we test are:

Ceramics

Metals, metal alloys, & metal-plated materials

Nanofluids & colloids

Graphite & graphite-impregnated compounds

Plastics & polymers

Liquids & liquid mixtures

Powders & powder mixtures

Soil, dirt, & environmental products

Epoxies, resins, & glues

Thermal interface materials

Gels, creams, & pastes

Concrete, asphalt, & firebrick

Insulation, insulating foams, & other insulating products

Our Capabilities

Dynalene can measure specific heat capacity from a temperature range of -80°C (-112°F) to 1,600°C (2,912°F). Depending on your sample type or preferred method, we can tailor the test to meet your needs. If your testing temperature falls outside our temperature range, please contact us and we may be able to satisfy your request.

MATERIALS

Solids, liquids, pastes, powders

TEMPERATURE RANGE

-80°C to 1,600°C (-112°F to 2,912°F)

ACCURACY

± 5% (depends on material)

REPRODUCIBILITY

± 3% (depends on material)

SAMPLE SIZE

5 mg to 30 mg per sample run

ADDITIONAL ASTM TESTS PERFORMED

E1269
E2716

We encounter lots of unique samples that may have unconventional testing requirements or specifications. If you are unsure what type of test or instrument is required to analyze your sample, give us a call and we’ll make sure it’s tested the way you want it.

What is specific heat?

Specific heat capacity is a property that essentially describes how much heat a material can store. More specifically, it’s the amount of heat needed to raise a unit mass of material by a single degree. So as an example, if you had a pot filled with 1 kg of water and wanted to heat its temperature by 1°C, it would require 4,184 Joules of heat. Some materials have high specific heat capacities, such as water or hydrogen, and other materials have low specific heat capacities, such as glass, copper, and lead.

MATERIAL

Specific heat, J/kg·K (room temperature)

HYDROGEN

14,310

HELIUM

5,193

LIQUID WATER

4,184

PARAFFIN

2,800

WOOD

2,700

SOLID WATER (ICE)

2,040

RUBBER

2,010

COTTON

1,300

AIR (DRY)

1,007

ASPHALT

920

CLAY

880

GLASS

835

COPPER

380

LEAD

130

Understanding the specific heat of a material is very important in heat transfer applications. Engineers have been trying to identify new material technologies with very high specific heats for thermal energy storage applications. The more energy that can be stored in a material means less material is needed, the system can be smaller, and the cost can be reduced. In the past decade there has been an increased focus in molten salt solar plants because of the high thermal storage capacity of certain salts. Mirrors reflect sunlight onto pipes carrying hot liquid salt, and this salt is eventually stored in big tanks where it remains hot because of the salt’s high heat capacity. The salt is then drawn off to create steam which powers a turbine to create electricity. It is important for the salt to stay very hot because the plant still needs to produce electricity when there is no sunlight.

Geothermal energy is another power generation process that utilizes the specific heat of the earth’s crust. Pipes carrying a heat transfer fluid are installed deep down into the earth where it is hot from the internal heating of the earth’s core. The heat transfer fluid removes the heat from the deep rock beds and carries it to the surface where it can be used to create steam.

One reason why water is such an excellent heat transfer fluid is because it can carry and expel a lot of heat per unit mass due to the high specific heat. In nature, the high specific heat of ocean water helps regulate the global temperature by preventing days from being too hot and winters from being too cold. Similarly in the human body, the high amount of water present in the blood helps regulate body temperature and keep us cool.

Instrument theory and further reading

Our differential scanning calorimeter works by measuring the amount of heat it takes to raise the temperature of a sample vs a reference. One sample pan is filled with the sample and placed in the cell. Another pan (empty) is also placed in the cell. Several precise temperature probes are placed throughout the cell and heat flow and temperature are measured.

After determining how much heat it takes to raise the temperature of the pan containing the sample, the reference pan is subtracted and the specific heat of just the sample can be calculated. Specific heat can be viewed as a function of time or temperature, and this makes it easy to identify phase transitions, endothermic/exothermic reactions, crystallization kinetics, and other thermal phenomena.